The present invention relates to improved wire coil designs for dynamo-electric machine components (e.g., stators for electric motors, generators, or alternators) and to manufacturing solutions for implementing such designs.
Dynamo-electric machines operate by exploiting the interaction of rotating magnetic fields with a magnetic part or rotor. For example, ac electric motors include armatures or a configuration of insulated wire coils in a stationary part or stator. Current flow through the wire coils generates magnetic fields in the space of the stator. The wire coils are wound around ferromagnetic cores or poles to enhance the strength of the generated magnetic field. Stator casings are often made from ferromagnetic laminates. Longitudinal slots in the stator casings usually define these poles. The poles generally are tooth-like cross sections that are rectangular or trapezoidal, but are invariably provided with cap-like lateral extensions or shoes at their top ends to enhance the concentration or passage of magnetic flux.
Flowing current of different phases through a progressive sequence of coils around the stator rotates the magnetic field generated in the stator. This rotating magnetic field imparts electromechanical torque to the rotor and turns the electrical motor shaft on which the rotor is mounted.
The operational characteristics of a dynamo-electric machine depend on the nature or properties of the generated magnetic field. These properties are determined by the particular structure or design of the slots, poles, and the wire coils used. Design features such as the shape of the slots (e.g., depth, widths, and curvatures) and the winding specifications (e.g., wire size, turns, and slot fill ratio), affect not only the performance and efficiency of the dynamo-electric machine, but are also relevant to dynamo-electric machine manufacturing costs and reliability.
Consideration is now being given generally to ways of providing solutions for improving uniformity and reproducibility in dynamo-electric machine component manufacture. Attention is directed to slot and pole shapes, and winding coil structures or designs, with a view to improve the performance of dynamo-electric machines, and to improve manufacturing costs and reliability.